The present invention relates to glassware for chemical laboratories and pertains particularly to an improved stopcock having an extractor.
Glassware in the form of vessels, flasks, tubing and the like is used extensively throughout chemical research and testing laboratories. It is often desirable that systems be set up connecting a number of vessels together for the transfer of liquids or gasses between vessels. Such systems utilize glass tubing for such transfer.
It is often necessary to control the flow of either gas or liquid to and from vessels and the like. Such control is normally accomplished by means of glass stopcocks. Where sealing is particularly critical, stopcocks utilizing a Teflon plug have been used. These however frequently freeze and cannot be either opened or closed. Such conditions can be hazardous where immediate opening or closing of a stopcock is essential.
Sometimes silicone grease has been used on such plugs. This however has the problem of contaminating the fluid with the silicone grease.
It is therefore desirable that an improved stopcock having releasing means be available.